Leaving the prison: A discussion of the Iterated prisoner`s dilemma under preferential partner selection

Outside prison agents do not only ehoose a game strategy but also a game partner. In this paper players are finite automata and willing to interaet only if their expected payoff exeeeds an endogenously evolving aeeeptable minimum. In the resulting behavioural strueture the initial population is subdivided aeeording to players' degree of exploitiveness. If the number of eooperators is at least two, eooperators will be better off than defeetors. If more sueeessful automata reproduce, simulations show that due to partner seleetion eooperative behaviour is irnmune to invading mutants even if the life-span of generations is short.